Process for making reinforced polyester laminates utilizing irradiation

ABSTRACT

Reinforced polyester laminates are made by building up a laminate from unsaturated polyester resin and reinforcing material, such as glass fiber matting, the laminate being sandwiched between two foils during the polymerization and curing, and the polyester resin being polymerized by irradiation with high-energy electrons. Preferably the laminate is provided with permanent foils, produced by applying foils of unsaturated polyester resin in partly polymerized state to the laminate on both sides thereof and then irradiating the composite laminate with high-energy electrons to complete polymerization, whereby the foils are firmly bonded to the laminate.

United States Patent Van Gasse et al.

[451 Mar. 28, 1972 PROCESS FOR MAKING REINFORCED POLYESTER LAMINATESUTILIZING IRRADIATION Inventors: Rene L. E. Van Gasse, Schoten, Belgium;Petrus J. C. A. Simonis, Maassluis,

Netherlands Assignee: N.V. Chemische Industrie Synres, Hoek von Holland,Netherlands Filed: Feb. 6, 1968 Appl. No.: 703,459

Foreign Application Priority Data I Netherlands ..67018l3 Feb. 7, 1967U.S. Cl ..l56/179, 156/206, 156/272, 156/277 Int. Cl ..B32b 5/00 Fieldof Search ..156/206, 272, 327, 179

3,250,642 5/1966 Parasacco et al. ..l56/272 X 3,424,638 1/1969 Marans156/272 Primary Examiner-Leland A. Sebastian Assistant Examiner-StephenJ. Lechert, Jr. Attorney-Waters, Roditi, Schwartz & Nissen 57 ABSTRACTReinforced polyester laminates are made by building up a laminate fromunsaturated polyester resin and reinforcing material, such as glassfiber matting, the laminate being sandwiched between two foils duringthe polymerization and curing, and the polyester resin being polymerizedby irradiation with high-energy electrons. Preferably the laminate isprovided with permanent foils, produced by applying foils of unsaturatedpolyester resin in partly polymerized state to the laminate on bothsides thereof and then irradiating the composite laminate withhigh-energy electrons to complete polymerization, whereby the foils arefirmly bonded to the laminate.

Al er a' 1 aw E em PROCESS F OR MAKING REINFORCED POLYESTER LAMllNATESUTILIZING IRRADIATION This invention relates to a process for makingreinforced polyester laminates.

In the conventional processes for making reinforced polyester laminates,particularly glass fiber reinforced polyester laminates, thepolymerization of the unsaturated polyester is effected under theinfluence of catalysts (usually peroxides) in the absence or presence ofmetal salts and/or amines as accelerators and with or without the supplyof additional heat.

As is well-known, the polymerization proceeds as a result of theformation of free radicals from the catalysts, which initiate thereaction.

It is known to cause polymerizations to proceed under the influence offree radicals produced by irradiation with highenergy energy electrons.Reinforced polyester laminates, however, have never been produced inthis manner.

The present invention relates to a process for making reinforcedpolyester laminates by building up a resin laminate from unsaturatedpolyester resin and reinforcing material, particularly fibrous material,on a substrate, wherein the polyester laminate is sandwiched between twofoils during the polymerization and the curing, and wherein thepolyester resin is polymerized by irradiation with high-energyelectrons.

in addition to the face that it is thus possible to work more quicklythan with the known methods, the final product can acquire greaterdegree of polymerization, so that a higher resistance to water and otheratmospheric influences is obtained.

As the material for the foils between which the laminate is sandwichedduring the polymerization and the curing, cellophane and saturatedpolyester resins are used (namely, polyterephthalic acid esters, Mylar,Dupont de Nemours; Melinex l.C.I.). The only purpose of these foils isto support the laminates during the polymerization and to preventcontact with the air, and they are again removed after the laminateshave cured. They can only be used once or a limited number of times.

According to co-pending application Ser. No. 619,933 now abandonedhowever, it is possible to replace the temporary foils by permanentfoils, namely, by using foils of unsaturated polyester resin. Thelaminates then have better weather resistance. These foils may be madein various manners, but particularly also by irradiation withhigh-energy electrons, for example, as described in co-pendingapplication Ser. No. 651,518 now abandoned, by applying a radiationenergy exceeding l X erg./g./sec., which makes it necessary for theequivalent ratio of unsaturated monomer to ethylenically unsaturatedbonds in the polyester chain to be between 1.0 and 1.7. In this way, themanufacture can take place in a few seconds, and a polymerization degreeof more than 90 percent can be obtained.

Preferably, therefore, the subject process is combined with one for themanufacture of polyester foils for use in making polyester laminatesprovided with a permanent polyester foil, namely, by sandwiching thepolyester laminate during the polymerization and the curing between twofoils of partly polymerized unsaturated polyester resin, and dischargingthe product as a unit with the foils after the irradiation of thelaminate with the foils.

In this embodiment, the unsaturated polyester resin used both for thelaminate and for the foils preferably has an equivalent ratio ofunsaturated monomer to ethylenically unsaturated bonds in the polyesterchain of from 1.0 to 1.7, and the partial polymerization of the foils ispreferably also effected by high-energy irradiation.

in this manner it is possible to obtain a polymerization degree of thewhole unit of above 90 percent.

Although the reinforcement of the polyester resins preferably consistsof glass fibers, it may in some cases by recommendable to replace thisfibrous material, either in part or in full, by a wire reinforcement.

Ju ia It is also possible to use paper as the reinforcement, which maybe printed with decorative patterns.

The partly polymerized polyester foils may be printed or colored beforebeing united with the reinforced polyester laminate by furtherpolymerization.

Apart from the irradiation step, the manufacture of the laminates may beeffected in any suitable manner. in the embodiment in which polyesterfoils are used, the manufacture is preferably as described in thefollowing example, that is, by using rollers, which may, however, bereplaced by metal belts.

The example describes the manufacture of corrugated polyester laminateswith reference to the accompanying drawing, which is a diagrammaticshowing of a side-view of ap' paratus for carrying out the methodaccording to the inventron.

Referring to the drawing, a film consisting of unsaturated polyesterresin, produced by the esterification of 1 phthalic acid anhydride 1mole fumaric acid and 2.2 moles propanediol-l .2 dissolved in styrene,is applied to each of the rollers A and A by means of the devices H andH. Both films are partly polymerized on the roller by passing them underthe electron radiators D and D, whereby an amount of energy of 2 X 10erg./g./sec. is absorbed.

Supplied to the nip between the rollers A and A is also a glass fibermatting E, which is on both sides sprayed with an unsaturated polyesterresin produced by the esterification of 1 mole phthalic acid anhydride 1mole propanediol- 2.2 moles propanedioll .2 dissolved in styrene.

The laminate B with the two foils or films C spray-devices C',discharged at the bottom of the rollers, is subsequently pressed intothe mold K by means of dies 1 and I, it being retained in the mold bysuction and further passing one or more electron radiators J, for it tobe polymerized with a quantity of absorbed energy of 4 X 10erg./g./sec., whereby the foils are firmly bonded to the laminate. Acorrugated laminate leaves the mold at L.

Screen plates G and G prevent the resin in the spray- F and H to bepolymerized prematurely under the influence of the radiation.

We claim:

1. A process for the manufacture of reinforced polyester sheetingcomprising impregnating a fibrous or filamentary reinforcing materialwith an unsaturated polyester composition comprising a solution of anunsaturated polyester in an olefinically unsaturated monomer, to producea resin impregnated sheet, applying a thermoplastic film to each side ofthe sheet and subjecting the thus obtained laminate to irradiation withhigh-energy electrons to polymerize and cure the unsaturated polyestercomposition to thereby bond said films integrally to the sheet.

2. A process according to claim 1 wherein the thermoplastic film isconstituted by a polymerized unsaturated polyester.

3. A process for the manufacture of reinforced polyester sheetingcomprising impregnating a fibrous or filamentary reinforcing materialwith an unsaturated polyester composition comprising a solution of anunsaturated polyester in an olefinically unsaturated monomer, theequivalent ratio of unsaturated monomer to olefinically unsaturatedbonds in the polyester chain being 1.0-1 .7, to produce a resinimpregnated sheet, providing two films of a polymerized unsaturatedpolyester obtained by polymerizing a solution of an unsaturatedpolyester in an olefinically unsaturated monomer, the equivalent ratioof unsaturated monomer to olefinically unsaturated bonds in thepolyester chain being l.0-l.7, applying the films to each side of thesheet and subjecting the thus obtained laminate to irradiation withhigh-energy electrons to polymerize and cure the unsaturated polyestercomposition, to thereby bond said films integrally to the sheet.

4. A process according to claim 1 wherein the reinforcement is aglass-fiber mat.

ment is paper, printed with a decorative pattern.

10. A process according to claim 3 comprising printing the polymerizedpolyester films before subjecting same to irradiation.

11. A process according to claim 3 comprising coloring the polymerizedpolyester films before subjecting same to irradiation.

2. A process according to claim 1 wherein the thermoplastic film is constituted by a polymerized unsaturated polyester.
 3. A process for the manufacture of reinforced polyester sheeting comprising impregnating a fibrous or filamentary reinforcing material with an unsaturated polyester composition comprising a solution of an unsaturated polyester in an olefinically unsaturated monomer, the equivalent ratio of unsaturated monomer to olefinically unsaturated bonds in the polyester chain being 1.0-1.7, to produce a resin impregnated sheet, providing two films of a polymerized unsaturated polyester obtained by polymerizing a solution of an unsaturated polyester in an olefinically unsaturated monomer, the equivalent ratio of unsaturated monomer to olefinically unsaturated bonds in the polyester chain being 1.0-1.7, applying the films to each side of the sheet and subjecting the thus obtained laminate to irradiation with high-energy electrons to polymerize and cure the unsaturated polyester composition, to thereby bond said films integrally to the sheet.
 4. A process according to claim 1 wherein the reinforcement is a glass-fiber mat.
 5. A process according to claim 1 wherein the reinforcement comprises metal wire.
 6. A process according to claim 1 wherein the reinforcement is paper, printed with a decorative pattern.
 7. A process according to claim 3 wherein the reinforcement is a glass fiber mat.
 8. A process according to claim 3 wherein the reinforcement comprises metal wire.
 9. A process according to claim 3 wherein the reinforcement is paper, printed with a decorative pattern.
 10. A process according to claim 3 comprising printing the polymerized polyester films before subjecting same to irradiation.
 11. A process according to claim 3 comprising coloring the polymerized polyester films before subjecting same to irradiation. 